Preparation method of high-quality anhydrous rare earth chloride and bromide

Abstract

The invention provides a preparation method of high-quality anhydrous rare earth chloride and bromide. The preparation method comprises the following steps: (1) carrying out pre-dehydration on the rare earth halide REX<3>-xH<2>O to obtain crude anhydrous REX<3>, wherein X is elemental Br and / or Cl, RE is any one rare earth element or two or more rare earth elements consisting of Y, Sc, La, Ce, Pr,Nd, Sm, Pm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, and x is no less than 0 and no more than 7; (2) vacuumizing the crude anhydrous REX<3> obtained in the step (1) under water-isolated and oxygen-isolated conditions; and (3) carrying out gradient heating on a system formed in the step (2) in a plurality of stages from 200-1500 DEG C, and carrying out distillation purification on the target objectREX<3> to obtain the high-purity anhydrous REX<3> with the absolute purity of more than or equal to 99.99%. According to the preparation method of the high-quality anhydrous rare earth chloride and bromide, different substances in a material are separated through process control, so the anhydrous rare earth halide with extremely high absolute purity is obtained; and the preparation method is relatively low in process cost, and easy for industrial production.

Description

technical field [0001] The invention belongs to the field of preparation of inorganic materials, in particular to a method for preparing high-quality anhydrous rare earth chlorides and bromides. Background technique [0002] Scintillation crystals are a type of crystals that emit visible light or ultraviolet light under the action of rays (X-rays, α-rays, β-rays) or high-energy particles (neutrons, etc.). It has a wide range of applications in exploration wells, non-destructive testing, safety inspections, etc. [0003] In the past 20 years, the research on halide scintillators has developed rapidly, and a large number of new scintillation crystals with high light output, good energy resolution or the ability to distinguish gamma and neutrons have emerged successively. Among them, LaBr 3 : Ce 3+ and LaCl 3 : Ce 3+ The representative rare earth halide scintillator materials have attracted widespread attention due to their high light efficiency, fast decay, high energy re...

AI Technical Summary

Problems solved by technology

However, due to the difficulty in dehydration of these materials, oxyhalides are easily formed during the dehydration process, and the finished products are easily deliquescent, which brings great difficulties to the preparation, packaging, storage, and crystal growth of raw materials.

At present, high-purity anhydrous rare earth halides that meet the needs of scintillator growth can easily sell for over ten thousand per kilogram in the market, while CeBr 3 The price per kilogram is more than 60,000 yuan. The high price has seriously hindered the development of the rare earth halide scintillator industry.

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